Telephone system



Aug. 12, 1930.

a. A. WALLACE TELEPHONE SYSTEM Filed sept. 29. 1927 `1,() into thelineo'rcuit thecord elrcut.V

f Y erates` the magnetoqzgftofim l pERTf'A; WALLACE,fFQCHICAGQQILiioISgiAssrGNoE.ToKELLOGGSWITCHBOARDNn (SUPPLY Company, OIVKCHIC'AGQ, ILLINoIs, A

' "A further featurev sfthe imorlooration into', the-line: circuit of ringing y earls forsrnmom ing the calledsubset"ber,'`

Another" feature i`sthe marinerf {Whieh` the Vcalling,subscriber"at atmagneto 7 @the Vensuing yspeifiaftion'ahdf appdd claims and fora morefrcomplyete understand-f g. ofmy nventiohffreference tnqay ibehadfto, the. accompanying ldrafving` oonrectou Witlrthe following Specification'.v `Reiferrng to the drawing,magetojtyp A siosta'tonsvv are shown at ,arid ar furnished with fthe n usual1 apparatus and, @ou neeted 4totythemain exehage'ovefr Conductors e and f andefandfrespective1y f These 'conj-y 1 duetors y terminate atr the irlaip exchange in @Ord'clrcul C tend a reall` to a: subscriber@ wsu/bstlatovll-AZK of. Y thek common battery ftypeql AniY operatojrfs; set Y provided for.theleordfcireut Q.andtisx` conjaected by 4means fof fthe"orderygwgree with ail operator@ seti( ass'ocatedwith Athev [TELErHQNEQsvY'sTEM f l coRPoRAtrIoNrorILLINOIS? 5;;

COmisfproVd'edto yejacefthe lamps S after I @ouR041@Multipleajackr*are algolprovide. The yoord l'oreutClpompres an' l plug Al?, -a ,callngialg LK adapted `to connect the :i operatorfg setv ad SL forlt'he. usual supervisory purpose aud Said; lamp u Li or lines', of

1y thef generator G `to "tlli'effsflibf". tion, through the rpatn L l dg, o

t answering QP; a: listningfkg o will: operate l th@ mageto: generator' '9% Qfjth" repeanihgJem-1gRqcgnff, throughgfth,"alternate'entaob conductor 2,

,u irate Vcontact 19 o a battery through the u o line circuit L is busy. ,The insertion of the from` battery through the lamp tor 21, normal contact 22 of neto. Current flowing `over this path causes current to be induced in the windings c and d to energize the relay LR. The energizing circuit being traced from winding c, over normal closed contact 3 of the rmlg rela RR, conductor 4, condenser 5,' Y ough t e winding of relay LR, conductor, normal contact 7, conductor 8, and` through the winding d back to the windin 'c of they repeating coil RC. The relay R energizes and closes its contact 9 to cause the signalling relay SG to be energized by current ilowing from battery` ound'V through relay SG, conductor 10, to at alternate contact 9. The relay Gr attracts its armatures to close contacts 11 and 19 and thereby closesk a locking circuit for iteelftraced fromrbattery through relay SG, f dosed conductor 14, `to ground at normal 'contact generator mgthe relay LR deenergizes and y, res its contact 9 to normal to close a circmt `:for the lamps Slvfvhich are caused to light by current own from battery through thesignals S, con uctor 16,` normal contact 17 of rela CO,conductorf18, alterf relay 'SG which did not A e when its voriginalenergizing circuitlwas broken vby the restoring ofl contact u-to the locking circuit previously traced, c@ conductor 20fto groundfatnormal con- 9. The operators at the positionswhere f`, lal1ps SV appear s [and one `of them will insert the answering pl" -of a cord circuit into the jack associated with a lamp' S to answer-the call. y

fthat. vthe plug `AP of the cord circuitC is inserted into the jack J to complete the call the contact 29 is moved to its alternate position and closes an energizing circuit for the busy signals BU traced from windinor of` the'y signals Allthe busy to ound at 29 of the jack `signals appearing at the different positions towhich the jacks J, lamps Sand busy signels BU are multipled operate toi'nform the rators at the different positions that the plu AP intothe jack J also closes an energizing circuit for the relay CO traced SL, conducthe listening keyfLK, conductor23, sleeve contacts ,of the Y connectedplug AP` and jack J, conductor 24, and through both windings Zandgh of relay CO toy ground'.A The relay CO 'has va highresistance winding h and a low resistlewindingl wh'ch when connected in series oiers'somuch' resistance to the Low of current that the lamp SL will not light, but

` It; relay A will operate. Relay CO opel-'J v l ating opens its normally closed contact17 alternate' contact 11, yconductor `12, Y contact 13 ofthe auxiliary relay AR,

`which opens `will notice. the signals f CP into thc jack by Placing to interrupt the circuit for the lamps S which are now effaced. Upon the attraction of the armature Vof relay CO, contact 15 assumes its alternate position and breaks the locking circuit for the relay SG which accordingly restores to normal. Contact assumes its `alternate position and closes an energizing circuit for the auxiliary relay AR traced from battery through alternate contact 25 of relay CO, conductor 26, relay AR, conductor 27, normal contact 19 of relay SG, conductor 20 to ground at normal contact 9 of relay LR. Current flowing over this path causes theT relay AR to operate to close a locking circuit for itself and is held energized by current flowing over the previously described path through the relay AR to round at alternate `Contact 28.

T e o erator at C next throws herV listening key K to connect the" operators lset O with the calling subscriber A so that the subscriber may inform the operator ofthe number of they subscriber to Whom she wishes to be connected. When the operator throws her listening key the contact 22 is opened the energizing circuit forl the relayV CO which restores to normal and breaks the energizing circuit for the relay AR which also restores to normal. `The subscriberat A and the operator are now connected in a conversational circuit through the eating coil RC, normal contact 3 of relay R, conductor m, connected plug AP and jack J, tact A of the ringback key RB, conductor' 31, alternate Contact 32 oi the actuated listening key LK, conductor 33, through the operators head set HS,y Winding 34 of the induction coil IC, conductor 35, alternate con-- jtact 36 of the'listening key LK, conductor 37, Vnormal contact 38 of key RB, the rin contacts of AP and J, conductor n, normf contact 7, and over conductor 8, to the repeat ing coil RC. The voice currents are induced into'the coils a and b and transmitted through the suhscriberssubstation in the `well 'known manner, battery currentbeing supplied from the battery 40 in circuit with the transmitter 41 and the winding 39 of the induction coil IC o'f the cperatorsset. Y l

The operator being informed that the subscriber at A is the desired party will note the busy signalBU to sce if'the line is idle. If'it is idle she will insert the Vcalling plug Jwhich will close the contact 29' to operate each of the positions at which theyl appear ground upon the multiple con- The operatorwill nent actuate her ringing key RK to operate the ringing relay RR of the line circuit L' to cause rinf ing current toI besuppliedto the called station A. Theringingrelay RR yis energized 'by current.

ductorv 41'.

p `flowing from battery, through the resistance42, conductor 43, a1-

tip contacts of the normal 'conthc busy signals BU' atV ternate contact 44 of jgthefflgy fftpjcon# ta'cts Of CP; and `J', codctorsmfand 45," attracts its armaturetoclose contacts 3f and* 7V to complete thefcircuit* forf the-ringing current which may-v be Vtraced from' grot/1nd,y through theV ringing(` gener1to1?Y ":Gf, 'conduc' andthe @this abandoned; 1f isubserifbrf Immediately-umntheisresffingof there;

Y returns her listening- `key LK tof nor t 25,

'at answers the call the kroperator@ fQInI'ne-ff' diately apprised fof `that' factfbe'caseherlisl tening `key is ystllgfact-liajed and "sh'e will? hear g perfltor d sh e t ,i117 disconnect thegoperatorsjset Offromilthe *con ,versational 5 Or heawlymmarked' l condctorfs learns that the snb'scribeha's' fansw verfaflternate d` jstor "110 keur .fo tsuperviseithl ,connectant pn thetermnaton co fwm'htteryrel fremanedfenergized', .condnc circintand ashilnty Ithe fhigh ",Ifesstance lthroughfzthellofwcWidingl;offtherelay CO," alternatijcontact `17; condvl'l'ctor;y alternate `frelafylLRwhich` establishes :a crcuitlfor. the to 'i groundfthroughjrelay ARR t: 'Relayf RR Y' relay SGas previouslydescribed? Therelayfify SGlcloses Ea locking circuit;v for;l itself traced: 1.

i ySG,'alternatecontactkll; @7m conductor FV12511 alternate Contact ".13 of relays)` tor :Q53 :touground atri alternate p contact `,fl-5i o :i I As soon rasthe subscriber y'cease energizes andreturns yto normali'breaking the fdrtherrelay SC Jcontact"; therelay, however, remains-'en ergzedggorer the ,previously tracedf ,holding y circutis established/fol @my f Winding hpoffthe relayY v C0;;This'shuntcircuit"femovesjenoughreef;.

fsistance #"fromgth'e circit tml allow lthe, lamp?? A i for the relays AR and m ilds key LK 26 make an recall before mithrows her listening key LK to find outV whether a recall or a disconnection is desired the circuits for the relays CO and CO are both broken and the relays return to normal. The relay COfbreaking the holdin circuits SG and the which return to normaland the relyxCO breaking the circuitsfor the relays and s SG and the lamp SL which all return to e normlso that when the operator removes the plugs AP and CP from theijlacks J and J and releases her listening key K all the apratus is in its normal position. The relays and ARare provided with copper sleeves to make them slow to release so that the relays SG and SG vwill restore 4to normal before p the contacts 13 and 13' have restored.- This is SL and SL from light.-A

to" prevent the lamps to signal a false recall when the operais returned to normal. It is obvious that if only nals SLor Sq will glow. y

Should either of the subscribers desire to the plugsare the jaca the 'procedure is the same asf-1s followed insignalling `for a disconnection` but whenflthe operator'presses her listening key Llfindinquires the wants of the party sigmening for aman She win be mideh mm i' Y fonia disconnection. The operator noticing 'granted and will complete the calling subscriber desires to recall the `operator before the' call has been comshe will operate her* hand generator mgljwhich will operate the relays inthe line cil-puit in the same manner as when signalling Vthe lilglited lamp SL will throw her'listening "l for the number wanted.

Assumin which is ofthe common'battery. ype and lo` cated at adistance exchange she will initiate thecall `and theproced'ure will be the same as in the-previously Y tor is informedof the number Wanted when shewill operate the order wire'key LO l which will connect by means 'of the order the operator will release i when will be caused "l ingf'fronibattery Awires the operator-s setO at the cordjcircuit Gt'the operator-s set O at the distant jexof the jack TJ assumes winding of CR, conductor 56 to amp SL` .Theoperator at the ,SL appears that the operator at the cord circuit touch the tip of thefplug` one of the subscribers sig-A l s nale foradisconnection only one ofthe sig-` taken from s upon the switchhook and wait until the call the calli 4Like-r -has been completed when she K 'and the calling subscriber lcanask` y that the subscriber A desires to converse with the subscriber-s 'substation' A"- i the subscriber. `lowedY in all cases where `the called line is at a ',dstanceexchange if it c Q. WK VIf the line is not busy she will insert traced call until the opera! y relay CO?, Relay ICO" of relay SR. The contact 55 its alternate position to close an energizing circuit for the control relay CR traced from battery through the ground at alternate contact 55. The relay CR operates and attracts its contact 58 which closes an energizing circuit for mal contact 57 through the lamp SL, normal contact 59 of relay DR, conductor 60 ground at alternate contact 58 of relay CR.

position where the lamp glowing and Y C `has lugged into the proper trunk jackand will i TP against the sleeve ofthe jack J 2 to test the busyconditimi of the called line. If the line is busy there will be a high battery potential on the sleeve contact of the jack J 2 which will flow through the `tip contact of the plug -'v1`1),lno1'l11alA 'con- 'will see it duction coil IC ywhich will produce thecharf acteristic click in the operators head set HS' by ,which she will vknow theline isbusy; and` so inform the operator at O i who will instruct they subscriber at A to replace her receiver willI ring `the calling subscriber back.` Theop will test the'line from time to time until she finds itidle when the -calllwill be completed` "as hereinafter described. y When the oper atorat O learns that the call has beencoxn-` pletcdshe willoperateher ring-back key the signal lamp SL? A which will be caused to glow by current flow? y ing from battery know v.tanzt 61 ofy relay DR, conductor 62 to ound y 'through the tertiary winding 68 of heinrl,

das

which will cause the ringing relay RR;to op crate. Current flowing from battery resistance 42, tipcontacts of J and AP, conductor n.anfl` ringing relay RR to ground. Relay op. crates to connect ringing current from' gencrater-G to the subscribers linerto summon This procedure may bemfolf thx-ou h is desired.

plugTBlinto the jack Jz land will actuate la plunger of the fourpart'y` ranging key. ERJJIQ frequency in condition for transmittirg nagy ing current to the called line. Assuming thaty generatcrg is ofthe proper .frequencmthewl operator will depress theplunger plunger is depressed.`

an energizing cu'- DR and CO will op` erated by,` current alternate contact 30 of key EL,"

C()2 is established to Aplane the ringing generator ofthe proponiv n.120 C with contactlca which will assume and-frap-` rnain in its alternate position until anot r Upon the insertionot the plugTP into the i ack J* cuit for the relays DR and y .and the said relays Allowng V:from battery` through relay DR, sleeve contacts of the ickf and plug toA ground through the y"winding of .fsideto theringing generator g3, 1z lteijnzite contactilcS-,n'ormel contact 7i, conductor'SJlteinatc contact' 690i?" L 5 The relay DR also attracts itsgeonmetgce.' The"opgerator't pefvergjthesubscribs alternate contactmof HB2 tofbattery and altemmalicontact 7 2, cdctoi 1, ringfconta'ote of ,e I'IOfzreStricted'toneepwith has 'respondei1 1 The conversationl circuit be traced 'e'pering Coilr windings 'ormai contact 3, conducto B, conductor 31, noi-'mall willite `.iiorn1li .poSitiong 'opening'- [the,"energizing 'E @uit QftherrelayiCR whichdeenerg'izerahdi 1y i jventionI Yd notflwis'hl'ft be i o it-lierepeatingv coil 11 y"flow i vionslyf istnt exchangewill notic'e'ffthe 121mg Willfi'eadily suggesttliemselves without designal lamp to indicate a call, a; signal Alai'np Mipafi'tinl'from the spirit 'andsc'ope ofthe apin said cord circuit, 4rneanslin said line cirpeide' claims. v` l t c i y cuit for returning said first means to normal ,'What I claim as new, and desire tdSellle and for preventing the operation of said sec- 5 bf Letters Patent` of 'the'United,Statesisz ond signal, said ,first means being, reoper- .lo

i 'f'telephone's'ystein-of tlie-clas'sdescribed n 'able to rendera portiono said secondmeans nding acalliig and a called subscribers 'inoperative to allow said second signal `to 'substation terminating ata main exchange, Y`operate to indicate a recall. circuits atsaid main exchange, repeat 6. A telephone system including acalling m coil's operatively 'connecting' said line cirand a called subscribers telephone line, line?, 4,cuitslwith said substations, a cord circuit for circuits associatedvvitli said telephone lines, intercnnectingsaid substations by means of' a cord circuit for interconnecting' said lines, "'sait line circuits, `asource of rin ing current a signal lamp for said line circuit, aline f" linecircuits,ameans in sai line circuits relay and a 'signalling relay, said'linerelay adapted to connect said source of ringingclli'fl controlled over said calling line and operi u relitto the called line,and o erator controlled able to energize said signallingrelay to opermeans in said `cord circuit or controlling the 'ate said line circuit signal lamp to indicate nieans'in saidline circuit. Y l a call, a cut-oli relay for said line circuit y `2. A telephone system of the class described o erable upon Vthe interconnection of lsaid includin la calling subscribers line `and a line circuit andsaid cordr circuit toeace said'fs called su scribers line terminating at a `mam signal, a second signal for said cord circuit,

Y exchange, line circuits at said main exchange said line and signalling relays ada ted 4to repeating'coils operatively connecting said o rate said second 'signal to signa "for a j 'line circuits with said subscribers lines,acord disconnection when sa1d line relayis ener- 25 r circuit for interconnecting said line circuits, gized after said line and cord circuits have go -asource of ringing current atY said 'line cireen connected; 1` I ciits, `individual connectingmeans in said 7. A, telephone s stem` including. line cirline `ci-rcuits,and'operator controlled means cuits, multiple cal ing signals for each of c in said cord circuitmfor actuating said con-f said linecircuits, multiple ]acks'and associat- 3 necting means to connect said `source of ringed multiplevisual signals for each of said lin 95 finglnrrentto said subscribers lines."` y t lcircuits,`fmeans controlled over oneof said telephone system of the class described lines' for operating its associatedmultiile A including a' pair of subscribers telephone calling signal, operator controlled means ior lines, ,line circuits for said subscribers lines operating the multiple visual signals associ- 5,-, nlocated at a main exchange, a cord circuit for ated with said line, and signalling means 11.11"!l 100 f interconnecting said lines, si als for said dividual to said line under operator control fcord circuit, a relay in each ok said line cir` forsignalling over said line. cuitsrliaving a low resistance winding and a' 8; A telephone system includin a.V line cirh resistancrwndg, @d means in Sd cuit terminating at the central o ce in mul- 4U Ql'cut fol" Shunting Saldhigh. Iestanc tiple jacks',"inultiple calling signals and m l" 105 jW'mdngt'o cause said signals in said cord tiple visualsignalsassociatedwithsaid jacks, j circuit to operate Ato signal for a recall. repeating coil connecting,V said Vjacks to said A4. 'A telephone vsystem of the class des line circuit, means `for applying signalling scribedincluding a calling subscribers line currentto said' line to cause the operation L 45 and a called subscribers line, aline circuit of said multiple callin l signals, and ,operi 110 'foreach of said lines, a cord circuit for n-rl ator controlled means or etfacing said c allterconnecting said lines, asignal lamp for ing signalsand for operating said visual each of saidV line circuits, a'signal lamp for signals,f A y r' y A t 1 V l, said cordcircuit, means in said line circuit 9; A telephone system including a linge` f 5a 0 fable t0 actuate said signal lampin Sald circuit Yterminating `at the central olice in' 115 e circuitv when a coil is initiated, a' relay fOrj multiple jacks, multiple calling signals and sadline circuit operable upon .the connection multiplevi'sual signals associated Vwith said Vof said cord circuit-,Ato said line circuit to elace jacks, a repeating coilconnekztingsaidjacks i t Signal 1&1? Y and retulnfsald'fst means to said line circuit', means for applying 'sig- `3 5 txilllqrmal, sai first 'means controlled over; nalling current to said line to cause theopeii' 120 S81f1"`$11b50fb01"s line and adapted tdbe rel' ation of said multiple callin signals, operoperatedwtoactuate-said si allamp lnsaidfator controlled means for e acingsaid cal1- ,l cord circuit'to signal for a isconnection. ing signals' and for operating said visual ,r A telephone system includinga s ubsignals, and ringing control apparatuaindif 60 `scribers line, aline circuit associatedivvith yvidual to the line under operator control for 125 said subscribers line,"a cord circuit foi-' consupplying signalling current tliro h saidre- ,iiectiitig said subscribers line to othersubpeating coil to saidline for signaling therelines, a signal lamp for said linecirfover.

A' cuit,- means in said'line 'circuit controlled` ,$10. A telephone system including a line l5 over said subscribersline foroperating'said "circuit terminating at the central otlice in 130 Y p A1'`,1-z2,nwr multiple jacks, multiple calling signals "i multiple Visual signalsjassocated,With said Y jacks, a repeatingxco'il connecting said jacks v to said'line circuit,- means yfor applying sigcord circuit provided With-a supervisorysig l nal controllable byrapparatusindividualto nected to said line circuits,

i n e at each of said substations Y tions line circuitfa 'second k'sourcewofpower nailing current vto said line to cause the operation of saidmultiple calling signalsyoperator controlledmeans for Veilacing said calling signals and for operatngsaid visual signals,y ringing control apparatus vindividual to theV line under operator control `for supplying signailing current through: said repeating coil 1 tosaid line for signalling thereoi'zer, and a and associated with said multiple jacks? 11. A telephone system including line cir-l' Chicagoyin the county of i 

